Scientists have found a way to beat the menopause by waking up dormant follicles, offering new hope to women who run out of eggs early in life.
The experimental technique has been tested on a group of infertile women who reached the menopause at around the age of 30.
Of the 13 treated women, one has given birth to a healthy baby boy while another is said to be pregnant. Until now the only option available to women with this form of infertility has been to accept IVF treatment using donor eggs, which means raising a child with another biological mother.
The researchers now plan to see if the technique can help other categories of women, including those affected by cancer treatment, and who become infertile between the ages of 40 to 45.
Around 1pc of women suffer from a condition called primary ovarian insufficiency which brings on the menopause at a very young age.
The "In-Vitro Activation" (IVA) technique involves removing the ovaries, cutting them into small one to two millimetre square cubes, and treating the fragments with special stimulating drugs for two days.
The fragments are implanted in the Fallopian tubes and hormones administered to trigger egg development.
Lead scientist Dr Kazuhiro Kawamura, from St Marianna University School of Medicine in Kawasaki, Japan, said: "For patients with primary ovarian insufficiency, egg donation is the only option for bearing a baby.
"These patients are eager to find a way to become pregnant with their own eggs. I hope that IVA will be able to help patients with primary ovarian insufficiency throughout the world."
The research builds on work in the laboratory showing that women who suffer premature menopause still retain tiny, dormant, "primordial" follicles.
Arousing these immature follicles can result in women previously thought to have untreatable infertility producing viable eggs.
A total of 27 Japanese women with primary ovarian insufficiency took part in the study and had both ovaries removed by keyhole surgery.
Of these, 13 were found to have ovaries containing dormant follicles.
Follicle growth was observed in eight cases, the scientists reported in the journal Proceedings of the National Academy of Sciences.
Eventually five women developed mature eggs that were collected for in-vitro fertilisation. One woman received an embryo but failed to become pregnant. Another was still pregnant, said the researchers, and a third who received two embryos had given birth to a healthy baby boy.
Dr Kawamura himself performed a Caesarean section on the woman who gave birth.
"I could not sleep the night before the operation, but when I saw the healthy baby, my anxiety turned to delight," he said.